This invention relates to a toggle solenoid valve for controlling fluid flow through valve ports, and in particular, to a toggle solenoid valve having an electromagnetic pole piece and toggle assembly.
Solenoid valves commonly utilize either a plunger or a toggle-style assembly for valve actuation. It is believed that the plunger-style solenoids offer good power to force efficiencies but are difficult to design when trying to achieve minimum upsweep or dead volume. Toggle-style valves offer an alternative to minimize the upsweep or dead volume but may sacrifice the power to force efficiencies in the plunger-style solenoid valve.
Toggle-style solenoid valves typically utilize coils which are electromagnetically coupled to a pole piece or a core assembly and a moving armature. The armature is typically displaced or preloaded to a fixed gap using a spring element. The armature is then coupled through a membrane to a valve section typically having three ports: common, normally closed, and normally open. Alternatively, the valve can be configured with only two ports by omitting the center port. The armature serves as a poppet to the valves. Alternatively, the armature may have poppets connected to it. When the coils are energized, the armature moves or rotates to release the valve of the normally closed port and engage the valve on the normally open port. If the assembly includes a common port, the common port will be in communication through a pathway with the normally open port until the coil is energized and the armature moves, whereupon the common port will then be in communication with the normally closed port. It has been known to have the armature pivot around a fixed point when rotating upon actuation.
In a common arrangement, the armature will be biased by a coil spring providing the fixed gap between the armature/poppet and the normally open port and closing the normally closed port as is shown in U.S. Pat. Nos. 5,653,422 and 5,762,097.
It has also been known to provide a toggle-type valve that includes a pair of elastomeric support arms extending from a cover surrounding a rigid core as is shown in U.S. Pat. No. 6,394,136. The '136 Patent also discloses actuation arms, which are attached in a levered manner to the support arms. Moving the actuation arms provides a torque to the support arms for pivoting the toggle valve. The support arms, actuation arms, cover and a frame are all made of elastomeric material. All movement of the valve assembly in the '136 Patent is provided by movement of the actuation arms as opposed to the magnetic attraction of an armature and an opposing spring as shown in the '422 and '097 Patents.